1. Field of the Invention
The present invention generally relates to fluid valves, and more specifically to a fluid valve having a plurality of inlet ports and a single outlet port or vice-versa, and a fluid supply system incorporating the valve.
2. Description of the Related Art
It is necessary in many applications to selectively connect one of a plurality of inlet ports which receive different fluids (liquids and/or gasses) to a single outlet port, or alternatively to selectively connect a single inlet port to one of a plurality of outlet ports. This has been accomplished in the past by connecting a plurality of discrete valves to a manifold or by means of a linear or rotary multi-port sequence valve.
The manifold system is disadvantageous in that volumetric dead spaces are inherent in the design which are difficult or impossible to purge. For this reason, manifold valves cannot be used in applications requiring selective supply of incompatible fluids such as solvents and acids.
Sequence valves can be designed with essentially no dead spaces. However, the ports can only be switched in a fixed sequence which is determined by the linear or rotary port arrangement.